Feeding device



Oct. 11, 1938. F. M. sLATER" FEEDING DEVICE 1 Filed April .'50, 1936 Hl S ATTORNEY.

I i UNITDSTATES Patented Oct. 11, 1938 n, 133,519 PATENTfoleri'cii*l y*Fred Slater, Phillipsburg, N. J., assigner to Ingersoll- Rand Company, Jersey City, N. J., a ycorporation of NewJersey Application April` so, 1936, serial Na. 77,153 f 8` Claims.

This invention relates to fluid actuated rock drills, and more particularlyto a feeding device for advancing a rock drill of'the'stoper type in accordance with'the penetration of the working element into the work. l

One object of the inventionV is to protect the rock -drill against injury. by its percussive element when the feeding device is fully extended and the working'implement'has been actuated out of the range of movement of the percussive element. f

A furtherv object is to `automatically reverse ne feeding element and to out offfthe supply of pressure fluid to the r'ock drill when the feeding device approaches or reaches a fully lextended condition.`

vOther objects will be in part obvious and in part pointed out hereinafter.

In the drawing accompanying this specification and in which similar reference numerals refer to similar parts,

Figure l is .a side elevation of a feeding device constructed in accordance, with the practice of the invention and arock drill to which` it is applied, I

Figure 2 is .an elevation; in section, of the feeding device,

Figure 3 is av transverse View vtakenthrough Figure 2 on theline 3--3,.and

Figures 4, 5 and 6 are elevations taken through Figure 3 on the lines 4-4, 5 5 and 6 6, re-

spectively.

Referring more particularly to the drawing, 29 designates the feeding device in its entirety, 2i a rock'drill connected to the feeding device, and 22 a working implement that extends 'into the rock drill 2! into .the pathofla hammer piston (not shown) whereby theworking implement is driven into the rock 23 fordrilling the'hole 24.

The drilling mechanism may be supported by any suitablel means, as'V for example a column 25 having a clamping 'device 26 that engages the feeding device 2|) and maintains the rock drill 2| in the correct 4operative position `with respect to the work 23.V

The feeding device 29,' constructed in accordance with the practice of the invention, com-` prises a cylinder 21 which, in the present instance, constitutes the stationary member and is held thus by the clamping device 26V.' The-cylinder contains a piston 28 having'opposed differential pressure ,surfaces 29 `and 30 and is connected to the rock drill 2| by ai rod 3|. carrying an external collar 32. Thecorresponding ends of the rod 3| andj the collar 32 seat against a head block assembly Y33 comprising, in the structure shown, a series of plates 34, 35 Vand 36 of which the plate 34 lies adjacent the collar 32 and that designated 36 adjacent the rear `end of the rock drill 2| vfor which it forms a closure.

The plates constituting the head block assembly are held in assembled relationship with respect to each other, and with the rock drill 2| and the collar 32, by bolts3'l extending through these elements and serving to clamp them securely together.

Within the plate 36 is a valve chamber 38 containing a throttle valve 39, of the rotary type, having a bore 4U into which pressure fluid is admitted by a supply conduit 4| connected to the plate `36. The throttle valve 39 has a stem 42 projecting tothe exterior of the plate 36, and on the free end of the stem 42 is a lever 43 whereby the throttle valve 439 may be manually actuated.

The throttle valve 39 controls the admission of pressure fluid to both the rock drill 2| and the feeding device `2|J..V ToY supplythe former the plate 36 is provided with a supply passage 44 which may lead to the distributing valve (not shown) of the rockv drill, the vthrottle valve 39 having a port 45 to register with the passage 44.

In the periphery of the throttle valve 39 is a partly annular groove v46 which is in constant vcommunication withthebore 49 through a port 41 and registers with passages 48 and 49 that open into thevalve chamber 38 in the same transversel plane. The f passage 48 extends through the head block assembly and opens into a chamber 56 in the rod 3|, and .a passage 5| in the rodr 3| affordsV communication between the chamber 50 and a pressurechamber 52 in the cylinder 2'|.v

The passage 49 extends through the head` block assembly and through the collar 32 and the wall rof the rod 3| and opens into a tube 53 seated with one end into the plate 33 and with its other end in the portion of the rod forming an end sur'- face for the chamber 50. The interior of the tube constitutes a continuation of the passage 49 and said passage isextended through the lower or free end of the rod 3| and opens into an enlarged pressure chamber 54 in the lower or outer end of the cylinder 21. 'I'he passages 4,8 and'49 are so arranged that the groove 46'may simultaneously communicate with bothV and the pressure chambers 52 and 54 may, therefore, be placed in communication with pressure iiuid supply at the same time.

The throttle valve 39 is actuated manually, by means ofthe lever 43, tothe open position. Means are provided, however, to effect automatic shifting of the throttle valve for cutting off the supply of pressure iluid to the pressure surface 29 `when the feeding device approaches or reaches a condition of maximum extension. To this end the plate 36 is provided with a pistonA chamber 55 to accommodate a swing piston 56 keyed to the valve stem 42. The piston chamber 55 is sealed by a cover 51 secured to the plate 36, and a projection 58 on the cover 51 extends into the piston chamber 55 to form a head 59 for one end of the piston chamber.

An exhaust port 60 intermediate the ends of the piston chamber 55 provides an outlet for pressure uid employed for actuating the piston 56, and in the inactive end of the piston chamber is a vent 6| to maintain that end of the piston chamber in constant communication with the atmosphere.

The surface of the swing piston 56 adjacent the head 59 constitutes a pressure surface 62 to which pressure fluid is conveyed by a passage63 extending through the projection 58 and the head block assembly and opening into a tube 64 afiixed to the plate 33 and the rod 3|, in the manner of the tube 53. The interior of the tube 64 thus also forms a continuation of the associated passage 63, and said passage is continued through the rod 3| and communicates with the pressure chamber 52 through a port 65.

In order that the port 65 may be normally closed to prevent communication between the pressure chamber 52 and the passage 63 a valve 66, of the' sleeve type, is disposed upon the rod 3| and is normally held in position to seal the port 65 by a spring 61 seating against the valve 66 and the piston 28. The spring 61 serves to hold the valve against a shoulder 68 on the rod 3| and on the end of the valve lying adjacent the shoulder 68 is an external flange 69 which, when the feeding device approaches maximum extension, is engaged by a. head 18 of the cylinder 21 and caused thereby to uncover the port 65.

The flange 69, while of larger diameter than the rod 3| to permit of such engagement of the flange with the head 10', is of smaller diameter than the bore of the cylinder 21 to permit of the free passage of pressure fluid between the flange and the cylinder.

As a preferred form of construction, the throttle valve also performs the function of communicating the passages 48 and 49 with the atmosphere to permit the exhaust of pressure fluid from the pressure chambers 52 and 54. The throttle valve is, therefore, provided' with a groove 1| located in the same transverse plane as the groove 46 to register with the passages 48 and 49, the groove 1| being of an extent to enable it to be placed in communication with both passages at the same time. 'The throttle valve is further provided with a longitudinally extending groove 12 to communicate the groove 1| with an exhaust port 13 in the plate 36.

In addition to the throttle valve as a means for controlling the exhaust of pressure fluid from the feeding device, the drilling mechanism is provided with the usual rotation handle 14 anchored to the plate 36 and having a grip portion 15 which the operator grasps to hold the rock drill 2| against unauthorizedl rotary movement. The grip portion 15 and the handle 14 .have a passage 16 extending therethrough, and said passage 16 communicates with a passage 11 opening into the passage 49. l'

Communication between the passage 16 and the atmosphere is effected through a port 18 which is controlled by a valve 19, and a lever 86 pivotally connected to the grip portion 15 seats against the valve 19 and may be conveniently manipulate-d by the hand gripping the grip member 15 to open the passage 16 to the atmosphere. Thus, whenever the pressure within the pressure chamber 54 is found to be excessive, as

when the working implement is passing through a soft strata in the work and in which case there is danger of rifling the drill hole, the valve 19 may be unseated by means of the lever 8U to partially reduce the pressure within the pressure chamber 54.

The operation of the device is as follows: The throttle valve 39 is first actuated, by manual pressure against the lever 43, to the position illustrated in Figure to bring the groove 46 into registry with the passage 48. Pressure fluid then iiows through the chamber 50 and the passage 5| into the smaller pressure chamber 52 and acts against the pressure surface 30 to contract the feeding device and hold it thus preparatory to its Vcorrect arrangement with respect to the work.

When the drilling mechanism is correctly placed the throttle valve is rotated further-to also bring the. groove 46 into registry with the passage 49. Pressure uid then passes into the pressure chamber 54 to act against the larger pressure area 29 of the piston and simultaneously, or shortly thereafter, the port 45 is brought into registry with thepassage 44 to supply pressure iluidto the rock drillfor actuating it.

During the ensuing period of operation of the drilling mechanism the percussive element of the rock drill 2| drives the working implement 23 into the work, and as the working implement penetrates the Work the pressure fluid acting against the pressure surface 29 constantly acts to advance the drilling mechanism in accordance With the degree of penetration of the working implement into the rock and thereby maintains the rock drill in correct operative relationship with the working implement.

This mode of operation'will continue until the piston 28 reaches a position in the cylinder 21 in which the feeding device approaches full extension. The flange 69 will then engage the head 10- and as the piston, together with the rock Idrill 2|, continues its feeding movement the port 65 is drawn out of the plane of thevalve 66 and placed in communication with the pressure chamber 52. Pressure iluid then passes through the passage 63 into the cylinder 55 and acts against the actuating surface 62 of the piston 56 and actuates said piston for rotating the throttle valve.

The pressure fluid acting against the actuating surface 62 actuates the piston 56 in the mannerdescribed until said piston uncovers the exhaust port 60, whereupon the pressure fluid used for actuating the piston and the throttle valve is exhausted to the atmosphere through the port 60. The port 6l), it should be understood, is so located that the active side of the cylinder 55 is communicated with the atmosphere when the throttle valve reaches the position in which the groove 46 is moved out of registry with the passage 49 although still in registry with the passage 48.

In the new position of the throttle valve the groove 1| registers with the passage 49 and the pressure fluid previously entrapped in the chamberV 54 may then escape to the atmosphere. As soon asthe effective pressure within the chamber 54 drops below that in the chamber 52 the pressure fluid in the latter chamber, acting against the surface 30 of the piston, immediately retracts the piston and the rock drill in readiness for a subsequent drilling operation.

lAfter the feeding mechanism is again fully contracted the throttle valve may be further actuated in the direction of its closed position, by means of the lever 43. The groove 1| will th-en register with the passage 48 and both pressure chambers 52 and 54 will be open to the atmosphere through the passages in the feeding device and the throttle valve.

From the foregoing description it will be readily apparent to those skilled in th-e art that the only manual attention required by the drilling mechanism is that of shifting the throttle valve 39 to the open position at the beginning of a drilling operation. The drilling mechanism will then continue to operate without any further attention from the operator until the cycle of operations has been completed or until it is again intended to start another round of operation. Although, whenever the nature of the rock being drilled is such that the full feeding pressure acting against the surface 29 is found to be excessive, the valve 'I9 may be opened to reduce the pressure acting against the pressure surface 29 to a value consistent with good drilling results under the circumstances. When the working implement again encounters stable rock the valve i9 may be permitted to close and the drilling mechanism will then again adn Vance under full feeding pressure.

I claim:

1. A feeding device for rock drills, comprising a pair of relatively reciprocable members one of which is connected to the rock drill, pressure chambers in one of the members, opposed pressure surfaces on the other member, passages for conveying pressure fluid to and from the pressure chambers, a valve to control the passages and being manually actuated in one direction, an ach tuating surface on the valve, and means in one of the pressure chambers carried by one of the members and movable with respect thereto to valve pressure fluid to the actuating surface for actuating the valve in an opposite direction.

2. A feeding device for rock drills, comprising a pair of relatively reciprocable members of which one member is connected to the rock drill, pressure chambers in one of the members, opposed pressure surfaces on the other member, passages for conveying pressure fluid to the pressure surfaces to effect relative reciprocatory movement of the members, a valve to control the passages and being manually actuated in one direction, an actuating surface for the valve, and means carried by one of the members and actuated by the other member to valve pressure fluid from one of the pressure chambers to the actuating surface for shifting the valve in an opposite direction.

3. A feeding device for rock drills, comprising a pair of relatively reciprocable members of which one member is connected to the rock drill, pressure chambers in one of the members, opposed pressure surfaces on the other member, a rotary valve to control the flow of pressure fluid to the pressure surfaces to effect relative movement between the members and being manually rotated in one direction, a piston associated with the valve, and means carried by one member actuated by the other member for valving pressure fluid from one of the pressure chambers to the piston for rotating the valve in an opposite direction.

4. A feeding device for rock drills, comprising a pair of relatively reciprocable members of which one member is connected to the rock drill, pressure chambers in one member, op-posed pressure surfaces on the other member, passages for conveying pressure fluid to and from the pressure chambers, a valve to control the passages and having an actuating surface, a kicker passage in one of the members to convey pressure iiuid to the actuating surface, a valve to control the kicker passage, and means on one of the members to move the last mentioned valve for admitting pressure uid from one of the pressure chambers into the kicker passage for actuating the first said valve.

5. A'feeding device for rock drills, comprising a feeding cylinder, a piston in the cylinder having opposed pressure surfaces, a rod on the piston connected to the rock drill and having a plurality of passages for conveying pressure fluid into the cylinder on opposite sides of the piston to act against the pressure surfaces, a valve to control the passages and having an actuating surface, a kicker passage in the rod for conveying pressure uid from the cylinder to the actuating surface for shifting the valve, a valve on the rod to control the kicker passage, and means in the cylinder to effect shifting of the last said valve for uncovering the kicker passage.

6. A feeding device for rock drills, comprising a feeding cylinder, a piston in the'cylinder having opposed pressure surfaces, a rod on the piston connected to the rock drill and having a plurality of passages for conveying pressure fluid into the cylinder lon opposite sides of the piston to act against the pressure surfaces, a rotary throttle valve to control the passages, a lever on the throttle valve for rotating said throttle valve in one direction, a swing piston affixed to the throttle valve, a kicker passage in the rod for conveying pressure fluid from the cylinder to the swing piston for rotating the throttle valve in the opposite direction, a spring-pressed valve slidable on the rod normally preventing communication between the cylinder and the kicker passage, and means in the end of the cylinder to effect shifting of the last mentioned valve for communicating the kicker passage with the cyl* inder.

7. An extensible feeding device for rock drills, comprising a pair of relatively reciprocable members of which one member is connected to the rock drill, pressure chambers in one member, opposed pressure surfaces on the other member, passages for conveying pressure fluid to the pressure chambers, a valve to control the passages and being shiftable manually in on-e direction to admit pressure fluid into the passages, and means in one of the pressure chambers carried by one of the members and actuated by the other member to effect shifting of the valve in an opposite direction.

8. An eXtensible feeding device for rock drills, comprising a pair of relatively reciprocable members of which one member is connected to the rock drill, a piston on one member having opposed pressure surfaces, differential pressure chambers in the other member, passages for conveying pressure fluid to and from the pressure chambers, a valve to control the passages and being shiftable manually in one direction to supply pressure fiuid to the pressure chambers, and means in the feeding device carried by one mem.- ber and actuated by the other member to effect shifting of the valve for cutting off the supply of pressure fluid to and exhausting pressure fluid from the larger pressure chamber.

FRED M. SLATER. 

